Wiki info about T-34 (1942)

In 1942, a larger cast hexagonal turret was developed with two round hatches for the commander and the loader. The turret's armour was enhanced to a thickness of 52 mm in its frontal section. Its ammunition load was increased to 100 shells. Its operational range was also increased to 400 km by adding additional fuel tanks inside and outside the hull. The front-mounted 7.62 mm DT machine gun received an armoured gun mantlet. Depending on the factory that made them, the road wheels differed from each other in their appearance. Solid drop-forged rubber-coated wheels cast with reinforcing bars and circular apertures on the disc were used, both with and without bands. The tank was equipped with a more effective air filter system and an all-range fuel pump regulator. Unit commanders' vehicles were upgraded to the more powerful 9-R radio set from the 71-ТК-3 set. The T-34's mass increase from 28.5 tonnes to 30.9. The increased weight did not affect the vehicle's speed and manoeuvrability. The turrets, produced by the UZTM factory in 1943, were drop-forged from 45 mm plate. These turrets were easy to differentiate from others owing to their rounded upper edges. On the whole, the new changes lead to an increase in the tank's manufacturing ease, combat strength and manoeuvrability. In total, 23,332 of these tanks were manufactured with the upgraded turret.
Tanks of this model participated in all the operations of the Great Patriotic War from the end of 1942 to the Battle in Berlin. Furthermore, their proportion in tank brigades constantly grew, and by November 1943, brigades had become uniform groups of 65 T-34s. Captured tanks served in the armies of Finland, Romania, and Hungary and were actively used by the Wehrmacht and the Waffen SS. The latter had an entire battalion of T-34s, one of which was commanded by the notorious tank ace Emil Seibold, who destroyed around 40 tanks with his T-34.
The Polish Army, the Czechoslovakian corps and the army of Yugoslavia all received tanks of this model.